TextParaLineResult.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / DotNET / DotNET / 8.0 / untmp / WIN_WINDOWS / lh_tools_devdiv_wpf / Windows / wcp / Framework / MS / Internal / PtsHost / TextParaLineResult.cs / 1 / TextParaLineResult.cs
                        

                        
                            //---------------------------------------------------------------------------- 
//
// 
//    Copyright (C) Microsoft Corporation.  All rights reserved.
//  
//
// Description: Access to calculated information of a line of text created 
//              by TextParagraph. 
//
// History: 
//  04/25/2003 : [....] - Moving from Avalon branch.
//  06/25/2004 : [....] - Performance work.
//
//--------------------------------------------------------------------------- 

using System; 
using System.Diagnostics; 
using System.Collections.Generic;
using System.Collections.ObjectModel; 
using System.Windows.Documents;
using System.Windows;
using System.Windows.Media;
using MS.Internal.Documents; 

namespace MS.Internal.PtsHost 
{ 
    /// 
    /// Provides access to calculated information of a line of text created 
    /// by TextParagraph
    /// 
    internal sealed class TextParaLineResult : LineResult
    { 
        //-------------------------------------------------------------------
        // 
        //  LineResult Methods 
        //
        //------------------------------------------------------------------- 

        #region LineResult Methods

        ///  
        /// Get text position corresponding to given distance from start of line
        ///  
        ///  
        /// Distance from start of line.
        ///  
        internal override ITextPointer GetTextPositionFromDistance(double distance)
        {
            return _owner.GetTextPositionFromDistance(_dcp, distance);
        } 

        ///  
        /// Returns true if given position is at a caret unit boundary and false if not. 
        /// Not presently implemented.
        ///  
        /// 
        /// TextPointer representing position to check for unit boundary
        /// 
        internal override bool IsAtCaretUnitBoundary(ITextPointer position) 
        {
            Debug.Assert(false); 
            return false; 
        }
 
        /// 
        /// Return next caret unit position from the specified position in the given direction.
        /// Not presently implemented.
        ///  
        /// 
        /// TextPointer for the current position 
        ///  
        /// 
        /// LogicalDirection in which next caret unit position is desired 
        /// 
        internal override ITextPointer GetNextCaretUnitPosition(ITextPointer position, LogicalDirection direction)
        {
            Debug.Assert(false); 
            return null;
        } 
 
        /// 
        /// Return next caret unit position from the specified position. 
        /// Not presently implemented.
        /// 
        /// 
        /// TextPointer for the current position 
        /// 
        internal override ITextPointer GetBackspaceCaretUnitPosition(ITextPointer position) 
        { 
            Debug.Assert(false);
            return null; 
        }

        /// 
        /// Return GlyphRun collection for the specified range of positions. 
        /// Not presently implemented.
        ///  
        ///  
        /// ITextPointer marking start of range.
        ///  
        /// 
        /// ITextPointer marking end of range
        /// 
        internal override ReadOnlyCollection GetGlyphRuns(ITextPointer start, ITextPointer end) 
        {
            Debug.Assert(false); 
            return null; 
        }
 
        /// 
        /// Returns the position after last content character of the line,
        /// not including any line breaks.
        ///  
        internal override ITextPointer GetContentEndPosition()
        { 
            EnsureComplexData(); 
            return _owner.GetTextPosition(_dcp + _cchContent, LogicalDirection.Backward);
        } 

        /// 
        /// Returns the position in the line pointing to the beginning of content
        /// hidden by ellipses. 
        /// 
        internal override ITextPointer GetEllipsesPosition() 
        { 
            EnsureComplexData();
            if (_cchEllipses != 0) 
            {
                return _owner.GetTextPosition(_dcp + _cch - _cchEllipses, LogicalDirection.Forward);
            }
            return null; 
        }
 
        ///  
        /// Retrieves the position after last content character of the line,
        /// not including any line breaks. 
        /// 
        /// 
        /// The position after last content character of the line,
        /// not including any line breaks. 
        /// 
        internal override int GetContentEndPositionCP() 
        { 
            EnsureComplexData();
            return _dcp + _cchContent; 
        }

        /// 
        /// Retrieves the position in the line pointing to the beginning of content 
        /// hidden by ellipses.
        ///  
        ///  
        /// The position in the line pointing to the beginning of content
        /// hidden by ellipses. 
        /// 
        internal override int GetEllipsesPositionCP()
        {
            EnsureComplexData(); 
            return _dcp + _cch - _cchEllipses;
        } 
 
        #endregion LineResult Methods
 
        //--------------------------------------------------------------------
        //
        //  LineResult Properties
        // 
        //-------------------------------------------------------------------
 
        #region LineResult Properties 

        ///  
        /// ITextPointer representing the beginning of the Line's contents.
        /// 
        internal override ITextPointer StartPosition
        { 
            get
            { 
                if (_startPosition == null) 
                {
                    _startPosition = _owner.GetTextPosition(_dcp, LogicalDirection.Forward); 
                }
                return _startPosition;
            }
        } 

        ///  
        /// ITextPointer representing the end of the Line's contents. 
        /// 
        internal override ITextPointer EndPosition 
        {
            get
            {
                if (_endPosition == null) 
                {
                    _endPosition = _owner.GetTextPosition(_dcp + _cch, LogicalDirection.Backward); 
                } 
                return _endPosition;
            } 
        }

        /// 
        /// Character position representing the beginning of the Line's contents. 
        /// 
        internal override int StartPositionCP 
        { 
            get
            { 
                return _dcp + _owner.Paragraph.ParagraphStartCharacterPosition;
            }
        }
 
        /// 
        /// Character position representing the end of the Line's contents. 
        ///  
        internal override int EndPositionCP
        { 
            get
            {
                return _dcp + _cch + _owner.Paragraph.ParagraphStartCharacterPosition;
            } 
        }
 
        ///  
        /// The bounding rectangle of the line.
        ///  
        internal override Rect LayoutBox
        {
            get
            { 
                return _layoutBox;
            } 
        } 

        ///  
        /// The dominant baseline of the line.
        /// Distance from the top of the line to the baseline.
        /// 
        internal override double Baseline 
        {
            get 
            { 
                return _baseline;
            } 
        }

        #endregion LineResult Properties
 
        //--------------------------------------------------------------------
        // 
        //  Constructors 
        //
        //-------------------------------------------------------------------- 

        #region Constructors

        ///  
        /// Constructor.
        ///  
        /// Owner of the line. 
        /// Index of the first character in the line.
        /// Number of all characters in the line. 
        /// Rectangle of the line within a text paragraph.
        /// Distance from the top of the line to the baseline.
        internal TextParaLineResult(TextParaClient owner, int dcp, int cch, Rect layoutBox, double baseline)
        { 
            _owner = owner;
            _dcp = dcp; 
            _cch = cch; 
            _layoutBox = layoutBox;
            _baseline = baseline; 
            _cchContent = _cchEllipses = -1;
        }

        #endregion Constructors 

        //------------------------------------------------------------------- 
        // 
        //  Internal Properties
        // 
        //--------------------------------------------------------------------

        #region Internal Properties
 
        /// 
        /// Last character index in the line. 
        ///  
        internal int DcpLast
        { 
            get
            {
                return _dcp + _cch;
            } 
            set
            { 
                _cch = value - _dcp; 
            }
        } 

        #endregion Internal Properties

        //------------------------------------------------------------------- 
        //
        //  Private Methods 
        // 
        //-------------------------------------------------------------------
 
        #region Private Methods

        /// 
        /// Ensure complex data in line 
        /// 
        private void EnsureComplexData() 
        { 
            if (_cchContent == -1)
            { 
                _owner.GetLineDetails(_dcp, out _cchContent, out _cchEllipses);
            }
        }
 
        #endregion Private Methods
 
        //------------------------------------------------------------------- 
        //
        //  Private Fields 
        //
        //--------------------------------------------------------------------

        #region Private Fields 

        ///  
        /// Owner of the line. 
        /// 
        private readonly TextParaClient _owner; 

        /// 
        /// Index of the first character in the line.
        ///  
        private int _dcp;
 
        ///  
        /// Number of all characters in the line.
        ///  
        private int _cch;

        /// 
        /// Rectangle of the line within a text paragraph. 
        /// 
        private readonly Rect _layoutBox; 
 
        /// 
        /// The dominant baseline of the line. Distance from the top of the 
        /// line to the baseline.
        /// 
        private readonly double _baseline;
 
        /// 
        /// ITextPointer representing the beginning of the Line's contents. 
        ///  
        private ITextPointer _startPosition;
 
        /// 
        /// ITextPointer representing the end of the Line's contents.
        /// 
        private ITextPointer _endPosition; 

        ///  
        /// Number of characters of content of the line, not including any line breaks. 
        /// 
        private int _cchContent; 

        /// 
        /// Number of characters hidden by ellipses.
        ///  
        private int _cchEllipses;
 
        #endregion Private Fields 
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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